Opinion by Dr Peter D. Trolove
BVSc MSc (Aquatic Veterinary Studies) MBA
A recent report from Tasmania was as follows:- “In 2024, collaboration between the Centre for Aquatic Animal Health and Vaccines and the Australian Centre for Disease Protection, facilitated advanced genomic analyses of the bacteria which resulted in the isolation of the East Coast strain of the Tasmanian Rickettsia-Like Organism (TRLO-EC) being reclassified as Piscirickettsia salmonis (P. salmonis). This work was therefore able to determine that P salmonis has in fact been present in Tasmanian east coast waters since at least 2021 and in the south east zone (the ‘channel’) since 2023 based on samples submitted at those times. This means that this bacterium is naturally occurring in the east and southeast coastal waters and it is no longer regarded as an exotic emergency disease in Tasmania”
-Kevin de Witte Chief veterinary Officer Tasmania, 17 March 2025
Comment
This story is very typical of how diseases are spread by the aquaculture industry;
Because of limited technical support in the form of experienced fish vets and state of the art laboratories, the aquaculture industry has had a long and sorry record of transmitting fish diseases globally. Diseases such as bonamia (oysters), crayfish plague (freshwater crayfish), six different viral septicaemias of penaeid shrimp (prawns), furunculosis (Aeromonas salmonicida), Infectious salmon anaemia, Viral Hemorrhagic Septicaemia, etc. etc..
Antibiotics
Set up the farm, experience the disease(s), then spend the next decade attempting to diagnose and manage the problem with antibiotics and novel vaccines.
Plumes of pathogens are released from the sea cages along with parasites such as sea lice and the gill parasite Dactylogyrus to infect susceptible wild stocks of fish including trout and salmon.
Of course the wild stocks are left to die or survive on their own devices.
This is made worse by the industry being owned by a very small number of very large global players such as Unilevers, (the massive mainly Norwegian based Mowi group), Cooke Aquaculture (USA), etc.
These companies operate globally transferring fish and fomites (equipment) to all the parts of the world where they have a presence.
Like Putty
Politicians are putty in their hands mesmerised by the eye watering amounts of capital required to be in the game and the growth potential of the industry.
In the New Zealand case, Prime Minister Helen Clark facilitated the sale of the pick of NZ’s salmon farming hatcheries and marine farms to two Malaysian brothers who made their fortune chopping down the rainforests of North Malayasia and Sarawak. This duo also own many thousands of hectares of New Zealand exotic pine plantations under the Earnslaw blocks along with a majority ownership of New Zealand King Salmon.
Political Donations
Like other mega investors in NZ these guys cannot miss – donate a couple of hundred thousand dollars to the political party in power and receive $millions of taxpayer dollars as grants in return as is the case with the unproven deep water marine farm recently consented off the East Coast of the South Island.
Yet another case of privatising profits and putting the risk on the public.
The corruption becomes embedded when our government agencies are captured and/or silenced by our politicians.
An example of this lack of independence was NZKS’s funding for the Cawthron Institute to develop biosecurity plans for the New Zealand aquaculture industry.
Responsible politics does not involve (shallow) rhetoric and “cost saving”.
The mass salmon mortalities that occurred at NZKS’s Marlborough Sounds sites were similarly retrospectively found to have lesions caused by RLOs. While the New Zealand authorities had never previously identified this pathogen, in fact its presence was first identified by laboratories in Chile after NZKS sent samples to laboratories in that country, our experts just like those in Tasmania assumed the pathogenic organisms were already present in New Zealand. This “assumption” may have been made to avoid New Zealand having to declare an exotic disease incursion. This would have meant informing client countries risking a loss of market access for our farmed salmon.
Footnote: When Colin Taylor and I visited Wellington to learn of MPI’s position on trout farming, (a prominent political topic at the time), an MPI policy advisor told us that “MAF does not have a position on trout farming as we do not understand it”!
Fish farming is characterised by marginal economics which means in order to be viable, the strong tendency is to strive for maximum stocking and crowded fish stock running the risk of over-stocking.. That in turn, heightens the risk in crowded pens of fish diseases breaking out.
Shane Jones enthusiasm for fish farming (i.e. aquaculture) is quite frankly naive and doomed to fail.
Anything intensively farmed is open to disease you don’t have to look far to see that.
A disturbing article, but no surprises, corruption and greed, the too giants in our society.
The effect on wild, natural (unfarmed fisheries) salmon populations is detreimental.
With yearly exports of 1.2m tonnes, Norway is the largest producer of farmed salmon in the world. Norway’s wild salmon population has fallen from more than a million in the early 1980s to about 500,000 today.
The country’s salmon farm industry, which has had escapees of farmed fish and a significant rise in sea lice parasites, has been a big factor in reducing numbers to a historic low, resulting in the closure of 33 rivers to salmon fishing last summer.
Plus the escapees erode the genetic make-up of wild salmon.